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PubMed2025

Glioma mutational signatures associated with haloalkane exposure are enriched in firefighters.

BACKGROUND: Glioma is the most common malignant primary brain tumor and is associated with significant morbidity and mortality. Modifiable risk factors remain unidentified. New advances in exposure assessment, genomic analyses, and statistical techniques permit more accurate evaluation of glioma risk associated with exogenous occupational or environmental exposures. METHODS: By using whole-exome sequencing data from matched germline and glioma tumor samples, the authors compared tumor mutational signatures for 17 persons with glioma and a documented occupational history of firefighting with those of 18 persons with glioma without an occupational history of firefighting. All 35 individuals were participants in the University of California, San Francisco Adult Glioma Study. RESULTS: There was a positive correlation among firefighters between the median number of sample variants attributable to single-base substitution signature 42, a single-base substitution mutational signature associated with haloalkane exposure (from the Catalogue of Somatic Mutational Signatures in Cancer) and firefighting years (p = .04; R2 = 0.29). Among nonfirefighters, the individuals with the highest number of median variants attributable to single-base substitution signature 42 also had occupations that possibly exposed them to haloalkanes, such as painting and being a mechanic. CONCLUSIONS: In summary, the authors identified gliomas that had mutational signatures associated with haloalkane exposure that were enriched in firefighters and other occupations.

Humans↗

PubMed2024

A novel mutation in SORD gene associated with distal hereditary motor neuropathies.

BACKGROUND: Distal hereditary motor neuropathy (dHMN) is a heterogeneous group of hereditary diseases caused by the gradual degeneration of the lower motor neuron. More than 30 genes associated with dHMN have been reported, while 70-80% of those with the condition are still unable to receive a genetic diagnosis. METHODS: A 26-year-old man experiencing gradual weakness in his lower limbs was referred to our hospital, and data on clinical features, laboratory tests, and electrophysiological tests were collected. To identify the disease-causing mutation, we conducted whole exome sequencing (WES) and then validated it through Sanger sequencing for the proband and his parents. Silico analysis was performed to predict the pathogenesis of the identified mutations. A literature review of all reported mutations of the related gene for the disease was performed. RESULTS: The patient presented with dHMN phenotype harboring a novel homozygous variant c.361G > C (p.Ala121Pro) in SORD, inherited from his parents, respectively. A121 is a highly conserved site and the mutation was categorized as "likely pathogenic" according to the criteria and guidelines of the American College of Medical Genetics and Genomics (ACMG). A total of 13 published articles including 101 patients reported 18 SORD variants. Almost all described cases have the homozygous deletion variant c.757delG (p.A253Qfs*27) or compound heterozygous state of a combination of c.757delG (p.A253Qfs*27) with another variant. The variant c.361G > C (p.Ala121Pro) detected in our patient was the second homozygous variant in SORD-associated hereditary neuropathy. CONCLUSION: One novel homozygous variant c.361G > C (p.Ala121Pro) in SORD was identified in a Chinese patient with dHMN phenotype, which expands the mutation spectrum of SORD-associated hereditary neuropathy and underscores the significance of screening for SORD variants in patients with undiagnosed hereditary neuropathy patients.

Humans↗

PubMed2025

De novo rare EMX2 variants lead to idiopathic hypogonadotropic hypogonadism.

PURPOSE: The genetic etiology of infertility remains unknown. To identify genes for human infertility, we applied a de novo variant analysis in 142 parent-proband trios with idiopathic hypogonadotropic hypogonadism (IHH), an infertility disorder caused by gonadotropin-releasing hormone (GnRH) deficiency. METHODS: Rare de novo copy-number and single-nucleotide variants (CNVs and SNVs) were called from exome sequencing data of the IHH trios. An association study of common EMX2 variants and disease outcomes was performed in the Massachusetts General Brigham Biobank (N = 65,253). GnRH neuronal development and migration was studied in organotypic explants with knocked down of Emx2 and in a mouse model lacking Emx2. RESULTS: We identified that the gene EMX2 harbored both rare de novo CNVs and SNVs. Rare de novo EMX2 variants led to IHH, developmental delay, and hearing loss. Common EMX2 variants were linked to infertility, Parkinson disease, and hearing loss. Knockdown of Emx2 in nasal explants resulted in attenuated GnRH cell migration and GnRH cells were confined to nasal regions of Emx2 knockout (KO) mice, consistent with IHH pathogenesis. CONCLUSION: By utilizing a de novo variant analysis and cellular assays, EMX2 was uncovered as a gene for human infertility.

Humans↗

PubMed2025

Genomic characteristics and prognostic correlations in Chinese multiple myeloma patients.

BACKGROUND: Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of abnormal clonal plasma cells in the bone marrow. The heterogeneity in Chinese MM populations remains underexplored. METHODS: We conducted whole-exome sequencing (WES) on 241 tumor samples, complemented by RNA sequencing (RNA-seq) on 131 samples from 212 Chinese MM patients. RESULTS: We identified a novel mutational signature and analyzed molecular differences between newly diagnosed MM (NDMM) and relapsed/refractory MM (RRMM) patients. NFKBIA mutations were notably more frequent in NDMM patients compared to the MMRF-COMMPASS cohort (4/50 vs 22/937, p = 0.048), with additional recurrent mutations in several genes like TTN, IGLL5 and SYNE1. In RRMM patients, UBR5 mutations were more prevalent (4/24 vs 0/50, p = 0.01), alongside frequent mutations in OBSCN, CACNA1H, and HSPG2. Clonal evolution was assessed through multiple time points and locations, identifying genes potentially linked to circulating plasma cell formation. Cox regression analysis revealed that age and mutations in OBSCN and RB1 were significant predictors of progression-free survival (PFS) in NDMM patients. Additionally, albumin, β2-microglobulin, and RB1 mutations were correlated with overall survival (OS). CONCLUSIONS: In summary, we characterized the genomic landscape of MM in diverse Chinese populations, confirmed clonal evolution, and identified prognostic genes.

Adult↗

PubMed2025

Comprehensive analysis of a novel LYST mutation in a Tunisian patient with Chediak-Higashi syndrome.

BACKGROUND: Chediak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism, recurrent infections, bleeding tendencies, and progressive neurological impairment. The syndrome is caused by mutations in the LYST gene, which plays a crucial role in lysosomal trafficking. OBJECTIVE: This study aims to characterize the molecular basis of CHS in a Tunisian patient by identifying mutations in the LYST gene and analyzing their impact on the protein function, correlating these findings with the patient's clinical presentation. METHODS: A comprehensive clinical assessment was conducted on the patient, followed by biochemical, hematological, and microbiological analyses. Additionally, LYST protein levels were quantified in the patient and their parents using an ELISA assay. Genomic DNA was extracted from the patient's blood, and Whole Exome Sequencing (WES) was performed to identify mutations in the LYST gene. The findings were confirmed through Sanger sequencing, and bioinformatic tools were employed to predict the functional consequences of the detected mutations. RESULTS: The patient presented with classical symptoms of CHS, including silver hair, hypopigmented skin, recurrent infections, and neurological decline, with an unusually late onset at 18 years. ELISA results demonstrated significantly reduced LYST levels in the patient (1.8 ng/ml) compared to heterozygous parents (7.8 ng/ml and 8.1 ng/ml) and controls (9.2 ng/ml). Genetic analysis revealed a novel homozygous deletion, c.10269_10275del (p.Gly3424SerfsTer15), in the LYST gene, leading to a frameshift mutation and premature termination of the protein. Bioinformatic analysis demonstrated that this mutation leads to the deletion of five out of sven WD40 repeats in the protein's C-terminal region, which are critical for protein-protein interactions and lysosomal trafficking. CONCLUSION: The study identifies a novel LYST mutation in a Tunisian patient with CHS, expanding the spectrum of known genetic variants associated with the disease. The findings highlight the importance of genetic screening in populations with high consanguinity and underscore the need for targeted therapies to address the molecular defects in CHS.

Adolescent↗

PubMed2026

De Novo TRIO Missense Variants Disrupt Ras-GEF Domains and Cause Congenital Ventriculomegaly and Hydrocephalus.

Congenital hydrocephalus (CH), characterized by congenital ventriculomegaly (CV), affects approximately 0.5-1 per 1000 live births and is a common cause of pediatric neurosurgical intervention, yet its genetic architecture remains incompletely defined. We report a child with syndromic CH requiring cerebrospinal fluid diversion who harbored a pathogenic de novo missense variant in TRIO (c.3232C > T; p.(Arg1078Trp)), a gene previously associated with autosomal dominant neurodevelopmental disorders featuring variable head circumference. This case prompted systematic evaluation of TRIO variation in our CV/CH cohort (2,697 patient-parent trios) using exome sequencing. We identified five additional unrelated probands with de novo TRIO variants, including two novel substitutions affecting the same residue within the Ras-GEF1 domain (p.(Glu1299Lys) and p.(Glu1299Gly)), yielding significant gene-level enrichment for protein-damaging de novo variants (adjusted p = 6.12 × 10-5). All affected individuals exhibited CV, frequently accompanied by developmental delay and additional structural brain abnormalities. In silico structural modeling predicted that associated variants destabilize critical TRIO Ras-GEF domains required for Rho GTPase activation. Analysis of single-nucleus transcriptomic data from the developing human neocortex revealed enrichment of TRIO expression in multipotent progenitor populations. A systematic literature review identified six additional individuals with TRIO de novo variants and reported CV or CH, including an unrelated patient with the same p.(Arg1078Trp) substitution. Together, these findings expand the phenotypic spectrum associated with pathogenic TRIO variation to include CV/CH and support TRIO as a clinically relevant gene in the genetic evaluation of syndromic CV/CH patients.

Humans↗

PubMed2024

Identification of a novel intronic variant in COL4A2 gene associated with fetal severe cerebral encephalomalacia and subdural hemorrhage.

BACKGROUND: Genetic variants in COL4A2 are less common than those of COL4A1 and their fetal clinical phenotype has not been well described to date. We present a fetus from China with an intronic variant in COL4A2 associated with a prenatal diagnosis of severe cerebral encephalomalacia and subdural hemorrhage. METHODS: Whole exome sequencing (WES) was applied to screen potential genetic causes. Bioinformatic analysis was performed to predict the pathogenicity of the variant. In in vitro experiment, the minigene assays were performed to assess the variant's effect. RESULTS: In this proband, we observed ventriculomegaly, subdural hemorrhage, and extensive encephalomalacia that initially suggested cerebral hypoxic-ischemic and/or hemorrhagic lesions. WES identified a de novo heterozygous variant c.549 + 5G > A in COL4A2 gene. This novel variant leads to the skipping of exon 8, which induces the loss of 24 native amino acids, resulting in a shortened COL4A2 protein (p.Pro161_Gly184del). CONCLUSION: Our study demonstrated that c.549 + 5G > A in COL4A2 gene is a disease-causing variant by aberrant splicing. This finding enriches the variant spectrum of COL4A2 gene, which not only improves the understanding of the fetal neurological disorders associated with hypoxic-ischemic and hemorrhagic lesions from a clinical perspective but also provides guidance on genetic diagnosis and counseling.

Female↗

PubMed2026

Xp21 contiguous gene deletion syndrome presenting as congenital adrenal hypoplasia: molecular diagnosis and clinical re-evaluation of a pedigree.

OBJECTIVE: To investigate the molecular etiology in a male child clinically suspected of congenital adrenal hyperplasia (CAH) with negative conventional genetic testing, and to elucidate the genetic characteristics of his pedigree. METHODS: Clinical data from the proband and his family members were collected. Molecular diagnostics proceeded sequentially: initial targeted CAH testing (CYP21A2 and POR sequencing/MLPA, plus targeted NR0B1 CNV analysis) was followed by whole-exome sequencing coupled with genome-wide CNV analysis. RESULTS: The proband presented with neonatal cyanosis and hyperpigmentation. Laboratory tests showed markedly elevated ACTH (354.68 pmol/L) and low aldosterone (57.24 pg/mL). Molecular genetic testing identified a hemizygous deletion of approximately 4.44 Mb at Xp21.3-p21.1 (chrX:g.27080000_31520000), encompassing the NR0B1, GK, IL1RAPL1, and DMD genes. CNV-seq confirmed that the mother carried a heterozygous deletion of 4.38 Mb in the same region, while the father and four maternal aunts showed normal genotypes. CONCLUSION: This study ultimately diagnosed the proband with Xp21 contiguous gene deletion syndrome. The adrenal insufficiency resulted from X-linked congenital adrenal hypoplasia (AHC) due to NR0B1 haploinsufficiency, rather than CAH. These findings highlight the considerable clinical overlap between AHC and CAH, indicating that CNV analysis of the Xp21 region should be included in the diagnostic workup for male infants with suspected CAH but negative routine genetic testing. This provides a basis for the precise diagnosis and genetic counseling of such patients.

Humans↗

PubMed2025

A founder variant in TBCB is associated with global developmental delay, autism spectrum, and spastic paraparesis.

PURPOSE: Hereditary spastic paraparesis (HSP) is a genetically diverse group of Mendelian disorders characterized by length-dependent axonal degeneration. Microtubule dysfunction is a known mechanism in HSP that impairs axonal dynamics. TBCB encodes tubulin-folding cofactor B (TBCB), which, along with TBCE, regulates αβ-heterodimer dynamics and neuronal axonal growth. Here, we describe a new form of complicated HSP caused by a founder variant in TBCB. METHODS: Exome sequencing revealed a homozygous c.589T>A p.(Tyr197Asn) variant in TBCB in a cohort of 10 individuals assembled through genematching tools. Protein function was assessed using Saccharomyces cerevisiae ortholog ALF1, and a CRISPR-Cas9-generated homologous mutant in Drosophila melanogaster. TBCB expression and localization were examined in fibroblasts using western blot and immunofluorescence. RESULTS: Participants displayed late-childhood-onset spastic paraparesis, global developmental delay, and autism spectrum. TBCB protein levels were reduced in affected fibroblasts. The ALF1 mutant in yeast increased benomyl sensitivity, resembling a loss-of-function phenotype. In Drosophila melanogaster, the homologous mutant led to reduced survival and impaired climbing ability. CONCLUSION: We describe a novel neurodevelopmental disorder with spastic paraparesis and a high carrier rate in the Ashkenazi Jewish population. Our results indicate that TBCB has a vital role in the development of central nervous system and potentially in axonal function in humans.

Humans↗

PubMed2026

Clinical, genetic and bioinformatic analysis of Saudi families with Joubert syndrome and related disorders.

BACKGROUND: Joubert syndrome and related disorders (JSRD) are clinically and genetically heterogeneous ciliopathies caused by pathogenic variants in over 40 genes, mainly encoding ciliary proteins. However, data on JSRD in the Saudi population remain limited. This study aimed to identify novel and reported JSRD-causing variants in Saudi families and analyze their potential functional impact on protein structure using advanced computational tools. METHODS: Patients with genetically or clinically confirmed/suspected JSRD were recruited according to ethical protocols. Clinical data were collected, and exome sequencing was performed, followed by Sanger validation of identified variant. Pathogenicity was assessed using bioinformatics tools, while conservation, expression and RNA structure analyses were conducted to evaluate the potential functional consequences. RESULTS: Homozygous variants were identified in three consanguineous Saudi families, including a novel stop-gain variant in KIF7 (c.2992 C > T; p.(Gln998Ter)), and novel splice-site variant in CEP104 (c.489 + 1G > A) and a previously reported splice-site variant in TMEM237 (c.869 + 1G > A). All variants were predicted to be pathogenic as per ACMG criteria and located in highly conserved regions, suggesting potential functional impact. RNA analysis suggested possible alterations in folding. CONCLUSION: This study identified three pathogenic variants in JSRD-related genes in Saudi families, including two novel variants. These findings expand the variant spectrum for JSRD, particularly in the Saudi population. Establishing a comprehensive regional variant database is essential for improving molecular diagnosis and genetic counseling in population with high consanguinity. Finally, these results highlight the need for further functional studies to validate their pathogenicity and elucidate their role in JSRD pathogenesis.

Humans↗

PubMed2026

Clinical and Genomic Characteristics of Mexican Patients with Early Onset Gastric Adenocarcinoma.

BACKGROUND: Gastric cancer is a leading cause of cancer-related deaths in Mexico, with a rising incidence of early onset gastric cancer (EOGC) in young adults. This single-center study aimed to describe the clinical and mutational characteristics associated with EOGC in Mexican patients, based on an age cutoff of 50 years. METHODS: Clinical information was retrieved from electronic records and compared between EOGC and late-onset gastric cancer (LOGC). Whole exome sequencing data from 50 patients were analyzed and compared between both groups to elucidate the genomic overview of EOGC. RESULTS: Clinical data from 2,034 patients were analyzed. Of those, 35.69% had EOGC, with higher proportions of women (52.50%), diffuse histology (74.38%), signet ring cells (79.90%), and advanced stages (IVB: 79.58%; all p <0.001). Multivariate analysis in young patients identified ECOG (hazard ratio [HR]: 1.49) and clinical stage (HR: 1.78) as independent prognostic factors that increased mortality risk. However, the presence of Helicobacter pylori (HR: 0.76) and participation in genetic counseling (HR: 0.61) were independent prognostic factors that decreased the mortality risk. The molecular profile of Mexican patients demonstrated a high prevalence of CDH1 mutations and SBS44 mutational signatures. CONCLUSION: Mexican patients demonstrated higher rates of EOGC compared to other ethnicities. Genetic counseling enhances the overall survival of patients with EOGC; efforts should be made to incorporate it into routine practice. Molecular profiling revealed high CDH1 and SBS44 prevalence; however, sample size limitations warrant caution.

Humans↗

PubMed2024

Evolving knowledge of red flag clinical features associated with TTR p.(Val142Ile) in a diverse electronic health-record-linked biobank.

PURPOSE: Previous studies have established red flags that raise clinical suspicion for the hereditary form of transthyretin amyloidosis (ATTRv). However, these have not been specifically evaluated for the most common associated variant, TTR p.(Val142Ile). METHODS: Using an ancestrally diverse electronic health-record-linked biobank with exome sequence data from 27,630 unrelated adults, we evaluated 9 ATTRv-related clinical features among TTR p.(Val142Ile)-positive and -negative individuals. RESULTS: Among 337 variant-positive individuals (median age 63, 60% female), 10 (3.0%) were diagnosed with amyloidosis. TTR p.(Val142Ile) was associated with increased odds of cardiomyopathy/heart failure (CM/HF), atrial fibrillation, polyneuropathy, carpal tunnel syndrome, and proteinuria, but only in individuals ≥60 years. These features were evident 1.7 to 7.7 years earlier in variant-positive vs -negative individuals (hazard ratio [HR] 1.37, P = 3.99 × 10-2; HR 1.78, P = 2.52 × 10-3; HR 1.78, P = 1.70 × 10-3; HR 1.81, P = 5.14 × 10-3; HR 1.60, P = 1.94 × 10-2, respectively). By age 50, the cumulative incidence of CM/HF was 3.5-fold higher, and by age 60, the incidences of CM/HF, polyneuropathy, and proteinuria were 2-fold higher in variant-positive individuals. CONCLUSION: This study clarifies red flags that are associated with TTR p.(Val142Ile) in an age-dependent manner. With modifying therapies being available, early diagnosis of ATTRv in variant-positive individuals through the recognition of key clinical features is paramount.

Humans↗

PubMed2026

Integrating Optical Genome Mapping into the Genetic Diagnostic Algorithm: Clinical Utility in Unresolved Autosomal Recessive Disorders from a Large Cohort.

INTRODUCTION: The identification of precise genetic etiologies is indispensable for the clinical management of monogenic disorders. However, conventional diagnostic methods and exome sequencing (ES) frequently fail to identify complex structural variations (SVs), leaving the genetic basis unexplained in approximately 30-60% of suspected cases. Optical genome mapping (OGM) emerges as a high-resolution technology capable of detecting cryptic SVs inaccessible to standard methodologies. METHODS: In this study, we evaluated the clinical utility of integrating OGM into the diagnostic algorithm for unresolved monogenic diseases. Following negative or inconclusive results from standard ES pipelines, OGM was applied to a targeted subset of patients (n = 7) selected from a comprehensive clinical cohort of 1,257 individuals with suspected genetic disorders. RESULTS: The integration of OGM identified candidate SVs that may represent the second allelic alteration in two distinct cases; however, confirmation through parental segregation analysis remains pending. Specifically, OGM identified an intronic insertion in the TTLL5 gene and a deletion in a putative regulatory region approximately 400 kb upstream of the NMNAT1 gene, both of which were missed by prior diagnostic testing. CONCLUSION: Our findings suggest that OGM has potential value in investigating the missing heritability of autosomal recessive disorders. By detecting candidate SVs invisible to conventional methods, OGM may warrant consideration as a complementary diagnostic approach following inconclusive ES; however, larger cohorts and confirmatory functional studies are needed to establish its clinical utility.

Autosomal recessive disorders↗

PubMed2026

A recurrent CCDC82 frameshift variant associated with syndromic neurodevelopmental disorder in a consanguineous Pakistani family.

BACKGROUND: Intellectual disabilities (IDs) are part of neurodevelopmental disorders (NDDs) and are genetically heterogeneous conditions characterized by impairments in cognition, learning, and adaptive functioning. Despite advances in gene discovery, many individuals, particularly those from understudied populations, remain without a molecular diagnosis. Recent reports implicate CCDC82 (HGNC: 26282) as an autosomal recessive ID gene, although the phenotypic spectrum and biological context remain incompletely defined. METHODS: Exome sequencing (ES) was performed in a consanguineous Pakistani family (PKMR06A) with four affected individuals presenting with moderate to severe ID. Variant segregation was confirmed by Sanger sequencing. In silico analyses, including pathogenicity prediction, protein structural modeling, and domain intolerance assessment, were used to evaluate the functional consequences of the identified variant. Spatiotemporal gene expression patterns were examined using bulk and single-cell human brain transcriptomic datasets. RESULTS: Clinically, affected individuals of family PKMR06A presented with early childhood global developmental delay, speech delay, hypotonia, gait abnormalities, spasticity, and mild facial dysmorphism. Genetic screening revealed a recurrent rare homozygous frameshift variant in CCDC82 (NM_024725.4): c.373del; p.(Asp125Ilefs*6), segregating with disease in all available affected individuals of the family. The identified c.373del variant was absent from the gnomAD database and was classified as pathogenic (PVS1, PM2, and PP1) based on ACMG/AMP criteria. The c.373del variant is predicted to introduce a premature termination codon, p.(Asp125Ilefs*6), leading to deletion of essential coiled-coil domains from the encoded protein, supporting a loss-of-function mechanism. In silico, transcriptomic analyses demonstrated preferential CCDC82 expression during prenatal human brain development, providing developmental context for the neurodevelopmental phenotype associated with the identified truncating variant. CONCLUSIONS: This study expands the mutational landscape of CCDC82 and provides additional clinical and molecular evidence supporting its role in autosomal recessive NDD. The findings reinforce the importance of CCDC82 in human neurodevelopment and highlight the value of genomic investigation in underrepresented populations.

Autosomal recessive↗

PubMed2026

Somatic mutations reveal hyperactive Notch signaling in prurigo nodularis.

Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by pruritic skin nodules of unknown etiology. Little is known about genetic changes in PN pathogenesis, particularly somatic events, which are often implicated in inflammatory conditions. We thus performed whole-exome sequencing on 54 lesional and nonlesional skin biopsies from 17 patients with PN and 10 patients with atopic dermatitis (AD) for comparison. Somatic mutational analysis revealed that PN lesional skin harbors recurrent somatic mutations in fibrotic, neurotropic, and cancer-associated genes that are absent in adjacent PN nonlesional skin. Nonsynonymous mutations were most frequently present in NOTCH1 and the Notch signaling pathway, a key regulator of cellular proliferation and tissue fibrosis. In contrast, NOTCH1 mutations were absent in AD. Somatic copy-number analysis, combined with expression data, identified recurrently deleted and downregulated genes in PN lesional skin, which are associated with axonal guidance and extension. Follow-up immunofluorescence validation demonstrated increased NOTCH1 expression in PN lesional skin fibroblasts and increased Notch signaling in PN lesional dermis. Finally, a multicenter analysis revealed increased risk of NOTCH1-associated diseases in patients with PN. In characterizing the somatic landscape of PN, this study highlights the potential role of Notch pathway dysregulation in PN pathogenesis and fibrosis.

Humans↗

PubMed2026

Comparative analysis of distinct genomic landscapes in young-onset gBRCA1/2 breast cancer.

Carriers of germline BRCA1/2 pathogenic variants (gBRCA1/2 PVs) have elevated young-onset breast cancer risk. To define the pretreatment genomic landscapes of young-onset gBRCA-associated breast cancer, we evaluated 136 treatment-naive tumors diagnosed before age 50 in the prospective POSH study and 66 noncarriers from The Cancer Genome Atlas. Using whole-exome sequencing, we analyzed somatic variation, allele-specific loss of heterozygosity (asLOH), homologous recombination deficiency (HRD), and single-base substitution (SBS) signatures. gBRCA1 and gBRCA2 breast cancers had high rates of asLOH but differed significantly in average HRD scores and median SBS composition of signatures SBS1 (aging-associated), SBS18 (ROS-associated), and SBS3 (HRD-associated). Compared with gBRCA2 tumors, gBRCA1 tumors with asLOH were significantly enriched for alterations in hallmark ROS, DNA repair, and epithelial-mesenchymal transition pathways. In ER-positive, HER2-negative tumors from gBRCA1/2 carriers compared with noncarriers, we found significant enrichment of RB1, TP53, FAT1, and MYC single-nucleotide variants, indels, and copy number variants associated with CDK4/6 inhibitor (CDK4/6i) resistance. Together, these findings demonstrate significant differences between gBRCA1- and gBRCA2-associated breast cancers, and preexisting CDK4/6i resistance mechanisms, supporting prospective trials comparing individualized therapy for gBRCA1 versus gBRCA2 carriers and comparing poly(ADP-ribose) polymerase inhibitors versus CDK4/6i for ER-positive gBRCA1/2-associated breast cancer.

Humans↗

PubMed2025

Genomic subtypes of non-muscle-invasive bladder cancer: guiding immunotherapy decision-making for patients exposed to aristolochic acid.

BACKGROUND: The limited genomic data on non-muscle-invasive bladder cancer (NMIBC) hampers our understanding of its carcinogenesis and development. Specifically, Aristolochic acid (AA), a potent human carcinogenic compound from aristolochia plants and commonly found in Chinese herbal medicine, has been extensively documented as being closely associated with the onset and progression of bladder cancer. However, the field of AA-induced NMIBC remains largely unexplored in terms of its genomic and molecular characteristics, as well as clinical therapeutic strategies. METHODS: To bridge this knowledge gap, we conducted a comprehensive study using a cohort of 81 NMIBC samples. We performed whole-exome sequencing (WES) and RNA sequencing (RNA-seq) to obtain detailed genomic and transcriptomic data. We subjected these datasets to genomic analysis and subtype analysis to gain valuable insights into NMIBC. RESULTS: By temporally dissecting mutations in NMIBC specimens, we identified a comprehensive mutational landscape of NMIBC and the associations of these mutations with recurrence-free survival. Additionally, we discerned four genomic subtypes of NMIBC: AA-like, FGFR3/HRAS, FGFR3 & chr9Del, and genome instability (GI). The AA-like subtype presented a high frequency of gene mutations along with a pronounced AA mutagenesis signature of SBS22 (Fisher test: P-value 3.5e-4, OR 25.25) even after temporal dissection. The FGFR3/HRAS subtype exhibited FGFR3 or HRAS mutations with few copy number alterations (CNAs). The FGFR3 & chr9Del subtype was characterized by the co-occurrence of chr9p and chr9q deletions as well as FGFR3 mutations, while the GI subtype showed a high frequency of CNAs. Notably, the AA-like and GI subtypes demonstrated better outcomes after immunotherapy, whereas the FGFR3/HRAS subtype showed poorer outcomes. CONCLUSIONS: Our findings provide novel perspectives on the genomics of NMIBC, unveiling four prominent genomic subtypes, each showing different outcomes following immunotherapy. TRIAL REGISTRATION: No. 2019PHB268-01 (retrospectively registered on February 14, 2020).

Humans↗

PubMed2026

Challenges of genomic testing for patients and clinicians in Latin America: Foundations of a qualitative multi-country study.

Genomic medicine is expanding across Latin America (LATAM), yet access to essential ancillary services such as genetic counselling remains limited. 'Latin-SEQ' is a study that provides whole exome sequencing (WES) for neuromuscular diseases across 18 countries, aiming to improve diagnostic rates and generate region-specific genetic insights. However, funding constraints exclude genetic counselling and cascade testing, raising concerns about equitable and harm-free care. This paper reports early findings from 'Latin-SEQ Plus,' a mixed-methods study exploring patient and healthcare practitioner (HCP) perspectives on WES and genetic counselling. Data were generated via surveys with patients and HCPs, and participatory workshops with HCPs across six countries. We found that patients strongly valued genetic testing for diagnostic clarity, improved care, and family planning. HCPs acknowledged the diagnostic benefits of WES but highlighted absence of local genetic counselling services, inconsistent pre and post-test practices, and uncertainty in managing incidental findings and variants of uncertain significance (VUS). Psychological impacts related to WES results are not always addressed, underscoring risks of psychological and emotional harm for patients. Access to WES and genetic counselling is limited in LATAM due to financial hardship and the absence of a clear genetic counselling infrastructure. Our findings also reveal a mismatch between patient expectations and HCPs' capacity to deliver comprehensive genomic care. We argue for urgent investment in genetic counselling infrastructure, HCP training, culturally tailored resources, and policy frameworks to support equitable implementation of genomic medicine in LATAM.

Humans↗